Electophysiological techniques are used to measure the visual function of patients with ocular diseases or lesions in the visual pathways. New developments and applications of these techniques are designed to enhance their diagnostic value. The data obtained are correlated with those yielded by psychophysical tests of visual function and other ophthalmic diagnostic methods. The results obtained contribute to the diagnosis of ocular and neural disorders that affect vision and are needed to characterize the effects of different forms of treatment on the outcome of these diseases.